/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Copyright (c) 2022 Huawei Device Co., Ltd.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */
import CharsetProber      from './CharsetProber';
import CodingStateMachine from './statemachine/CodingStateMachine';
import HZSMModel          from './statemachine/HZSMModel';
import ISO2022CNSMModel   from './statemachine/ISO2022CNSMModel';
import ISO2022JPSMModel   from './statemachine/ISO2022JPSMModel';
import ISO2022KRSMModel   from './statemachine/ISO2022KRSMModel';
import {ProbingState}     from './CharsetProber';
import SMModel            from './statemachine/SMModel';

class EscCharsetProber extends CharsetProber {
  ////////////////////////////////////////////////////////////////
  // fields
  ////////////////////////////////////////////////////////////////
  private codingSM:CodingStateMachine[];
  private activeSM:number;
  private state:ProbingState;
  private detectedCharset:string;

  private static hzsModel:HZSMModel = new HZSMModel();
  private static iso2022cnModel:ISO2022CNSMModel = new ISO2022CNSMModel();
  private static iso2022jpModel:ISO2022JPSMModel = new ISO2022JPSMModel();
  private static iso2022krModel:ISO2022KRSMModel = new ISO2022KRSMModel();

  ////////////////////////////////////////////////////////////////
  // methods
  ////////////////////////////////////////////////////////////////
  public constructor () {
    super();

    this.codingSM = new Array(4);
    this.codingSM[0] = new CodingStateMachine(EscCharsetProber.hzsModel);
    this.codingSM[1] = new CodingStateMachine(EscCharsetProber.iso2022cnModel);
    this.codingSM[2] = new CodingStateMachine(EscCharsetProber.iso2022jpModel);
    this.codingSM[3] = new CodingStateMachine(EscCharsetProber.iso2022krModel);

    this.reset();
  }

  public getCharSetName():string {
    return this.detectedCharset;
  }

  public getConfidence():number {
    return 0.99; // float
  }

  public getState():ProbingState {
    return this.state;
  }

  public handleData(buf:ArrayBuffer, offset:number, length:number):ProbingState {
    let codingState:number;
    let maxPos:number = offset + length;
    let tempIntArray = new Int8Array(buf);
    for (let i:number=offset; i<maxPos && this.state==ProbingState.DETECTING; ++i) {
      for (let j:number=this.activeSM-1; j>=0; --j) {
        codingState = this.codingSM[j].nextState(tempIntArray[i]);
        if (codingState == SMModel.ERROR) {
          --this.activeSM;
          if (this.activeSM <= 0) {
            this.state = ProbingState.NOT_ME;
            return this.state;
          } else if (j != this.activeSM) {
            let t:CodingStateMachine = this.codingSM[this.activeSM];
            this.codingSM[this.activeSM] = this.codingSM[j];
            this.codingSM[j] = t;
          }
        } else if (codingState == SMModel.ITSME) {
          this.state = ProbingState.FOUND_IT;
          this.detectedCharset = this.codingSM[j].getCodingStateMachine();
          return this.state;
        }
      }
    }

    return this.state;
  }

  public reset():void {
    this.state = ProbingState.DETECTING;
    for (let i:number = 0; i < this.codingSM.length; ++i) {
      this.codingSM[i].reset();
    }
    this.activeSM = this.codingSM.length;
    this.detectedCharset = null;
  }

  public setOption():void {
  }
}

export default EscCharsetProber;